/*
 * Copyright 2017 Huawei Technologies Co., Ltd
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package io.protostuff.runtime;

import java.io.IOException;
import java.util.Map;
import java.util.Map.Entry;

import org.springframework.util.ReflectionUtils;

import io.protostuff.ByteArrayInput;
import io.protostuff.ByteBufferInput;
import io.protostuff.Input;
import io.protostuff.MapSchema;
import io.protostuff.MapSchema.MapWrapper;
import io.protostuff.MapSchemaUtils;
import io.protostuff.Output;
import io.protostuff.Pipe;
import io.protostuff.ProtostuffException;
import io.protostuff.Schema;

public class RuntimeMapFieldProtobuf<T> extends RuntimeMapField<T, Object, Object> {
    private static java.lang.reflect.Field entrySchemaField =
        ReflectionUtils.findField(MapSchema.class, "entrySchema");
    static {
        entrySchemaField.setAccessible(true);
    }

    private RuntimeMapField<T, Object, Object> runtimeMapField;

    private java.lang.reflect.Field field;

    private Schema<Entry<Object, Object>> entrySchema;

    @SuppressWarnings("unchecked")
    public RuntimeMapFieldProtobuf(RuntimeMapField<T, Object, Object> runtimeMapField,
            java.lang.reflect.Field field) {
        super(runtimeMapField.type, runtimeMapField.number, runtimeMapField.name, null,
                runtimeMapField.schema.messageFactory);

        entrySchema = (Schema<Entry<Object, Object>>) ReflectionUtils.getField(entrySchemaField,
                runtimeMapField.schema);

        this.runtimeMapField = runtimeMapField;
        this.field = field;
    }

    @SuppressWarnings("unchecked")
    @Override
    protected void mergeFrom(Input input, T message) throws IOException {
        if (!ProtobufFeatureUtils.isUseProtobufMapCodec()) {
            runtimeMapField.mergeFrom(input, message);
            return;
        }

        Map<Object, Object> value = null;
        try {
            value = (Map<Object, Object>) field.get(message);
            if (value == null) {
                value = schema.newMessage();
                field.set(message, value);
            }
        } catch (Exception e) {
            throw new ProtostuffException(
                    "Failed to get or set map field " + field.getDeclaringClass().getName() + ":" + field.getName(),
                    e);
        }

        MapWrapper<Object, Object> mapWrapper = MapSchemaUtils.createMapWrapper(value);
        if (ByteArrayInput.class.isInstance(input)) {
            ((ByteArrayInput) input).readRawVarint32();
        } else if (ByteBufferInput.class.isInstance(input)) {
            ((ByteBufferInput) input).readRawVarint32();
        } else {
            throw new Error("not handler " + input.getClass().getName());
        }

        int keyNumber = input.readFieldNumber(schema);
        if (keyNumber != 1) {
            throw new ProtostuffException(
                    "The map was incorrectly serialized, expect key number 1, but be " + keyNumber);
        }
        Object key = kFrom(input, null);

        int valueNumber = input.readFieldNumber(schema);
        if (valueNumber != 2) {
            throw new ProtostuffException(
                    "The map was incorrectly serialized, expect value number 2, but be " + valueNumber);
        }
        vPutFrom(input, mapWrapper, key);
    }

    @Override
    @SuppressWarnings("unchecked")
    protected void writeTo(Output output, T message) throws IOException {
        if (!ProtobufFeatureUtils.isUseProtobufMapCodec()) {
            runtimeMapField.writeTo(output, message);
            return;
        }

        final Map<Object, Object> existing;
        try {
            existing = (Map<Object, Object>) field.get(message);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }

        if (existing != null) {
            for (Entry<Object, Object> entry : existing.entrySet()) {
                output.writeObject(number, entry, entrySchema, true);
            }
        }
    }

    @Override
    protected void transfer(Pipe pipe, Input input, Output output,
            boolean repeated) throws IOException {
        runtimeMapField.transfer(pipe, input, output, repeated);
    }

    @Override
    protected Object kFrom(Input input,
            MapWrapper<Object, Object> wrapper) throws IOException {
        return runtimeMapField.kFrom(input, wrapper);
    }

    @Override
    protected void kTo(Output output, int fieldNumber, Object key,
            boolean repeated) throws IOException {
        runtimeMapField.kTo(output, fieldNumber, key, repeated);
    }

    @Override
    protected void kTransfer(Pipe pipe, Input input, Output output,
            int number, boolean repeated) throws IOException {
        runtimeMapField.kTransfer(pipe, input, output, number, repeated);
    }

    @Override
    protected void vPutFrom(Input input,
            MapWrapper<Object, Object> wrapper, Object key) throws IOException {
        runtimeMapField.vPutFrom(input, wrapper, key);
    }

    @Override
    protected void vTo(Output output, int fieldNumber, Object val,
            boolean repeated) throws IOException {
        runtimeMapField.vTo(output, fieldNumber, val, repeated);
    }

    @Override
    protected void vTransfer(Pipe pipe, Input input, Output output,
            int number, boolean repeated) throws IOException {
        runtimeMapField.vTransfer(pipe, input, output, number, repeated);
    }
}
